A scheme to overcome diffraction limit in optical lithography via tunable plasmons is proposed. The plasmons are generated by a current-driven instability and are resonance amplified between the drain and source barriers of the transistor. A series of discrete deep subwavelength can be obtained by controlling the gate voltage. Thus, it is possible to realize lithography with a resolution over 1/100 vacuum wavelength and achieve arbitrary one-dimensional and even simple two-dimensional patterns. Our scheme works in the linear optics regime and is easy to be experimentally realized.